ACT! by Sage 2010 and the number to register.

Greetings, the following are the steps I did to install ACT! by Sage and a problem I found:

1. I installed ACT! by Sage 2010 in a user computer2. That same night, the user had problems with Windows and Computer asked to come back one day before the windows registry3. ACT! appears that has not been installed4. I Reinstall ACT! by Sage 2010 but when trying to use the license number to register it tells me that number was already used.

I need to find some file and delete it?

I need to delete something in the windows registry For use again lcencia number for activation?